Innumeracy, a scourge -----------------------
People often say: "You don't need to know anything about mechanics; you just need a good mechanic!" Mathematics is entirely different, despite what Luc Ferry, a former French education minister, seems to think. He recently declared (on LCI's morning show on February 15): "Mathematics is absolutely useless in everyday life. Like 90% of French people, I have never used—even for thirty seconds—anything I learned in mathematics throughout my school years." In a sense, he believes that having good mathematicians is enough and that the rest of society can make do with a woeful grasp of the subject. Calculators and other modern tools will make up for this deficiency. This is completely false: numeracy is necessary in everyday life, opens the door to a great many jobs, and even enables us to fulfil our duties as citizens. Innumeracy is to arithmetic what illiteracy is to reading. It is increasing in France, where an estimated 10% of the population is affected. Unlike illiteracy, it is found even among the affluent, and an estimated 70% of adults are uncomfortable performing simple calculations. The Villani–Torossian report (see Tangente 181) is a breath of fresh air: let's hope it leads to action—urgently!
A good citizen must be numerate ----------------------------------
We often forget that numeracy is essential to becoming an informed citizen. How many politicians base their campaign speeches, and how many journalists their editorials, on economic data and percentages? How can we form an objective opinion if we do not understand what those figures represent? Such speeches make particular use of large numbers. When we are told that France's social-security deficit stood at €5.1 billion in 2017, and its national debt at €2,255 billion in the first quarter of 2018… how can we grasp these numbers (journalists would call them "figures") without quickly relating them to the French population? For France, one billion euros works out to roughly €15 per person. If you cannot do arithmetic, a polished argument can mislead you. Worse, it can sometimes have the opposite effect, leading you to reject all reasoned argument and become enthralled by often-hollow populist rhetoric. Reference: Questions de maths utiles. Hervé Lehning, J’ai lu, 2013.
Arithmetic in the workplace -------------------------------------
Good career guides for school leavers make the point clearly: many professions require a solid grounding in mathematics. What is sometimes overlooked is that many other occupations, seemingly far removed from mathematics, also require confidence with arithmetic. It may be used directly, as in many secretarial and accounting jobs. In other fields, it provides a foundation for professional practice and helps reveal its limitations. A doctor, for example, will be better able to assess the reliability of a drug, test, or vaccine with some knowledge of statistics and their paradoxes (see Mathématiques et Médecine, Bibliothèque Tangente 58). Our British neighbours have devoted more attention than we have to the economic importance of numeracy and have estimated that shortcomings in this area cost their GDP several billion pounds. How many poor decisions stem from mistaken estimates or approximations and result in substantial losses for businesses! Calculators and software are, of course, essential aids, but only a quick estimate of the expected result and the orders of magnitude involved can reveal a data-entry error or misuse of the machine.